Software Requirements; Speed Control; Elevation Control - GE T2100-ST1 Service Manual

Theory of Operation
full elevation. No closed loop control is done for positioning
elevation.
Power may be removed from the unit by opening the normally
closed switch connected to the emergency stop input, or by
removing AC power from the system. In both cases, the outputs
will be put into a non-energized state that will correspond to the
belt being shut off and the elevation motor being disengaged.

Software Requirements

The following sections describe the software commands that the
hosts system uses to control the T2100-ST series' speed and
elevation.

Speed Control

The host will send a speed command "SXXX0<CR>" to the
processor board. The firmware in the micro controller will
translate this command into a data frame, enable the drive if it is
not already enabled at this moment, and send the frame through
its drive serial interface. The drive will interpret the data frame
and will answer with data ACK or NACK, depending on the
transmission condition. The speed range is 0.0 to 15.0 mph (0.1 to
24.14 km/h).
Two outputs are required for speed control. The belt enable
output must be energized to put the belt into a run mode. The
speed control output is a 4kHz 1024 count pulse width modulated
(PWM) output supplied directly to the motor controller. Based on
calibration, the speed is controlled by outputting a PWM speed
reference to the motor controller and enabling the belt run
output. The speed inputs are averaged over a two-second period
to provide measured speed accuracy of 0.01mph or less.
If the speed of either input is measured to be more than 0.5mph
over the set point, or the difference between speed inputs is
measured to be more than 0.5mph, the belt will shut off
automatically. If the speed measured is more than 3mph over
the set point, the belt enable signal will be turned off
immediately. If the motor controller activates a fault signal to
the UPS, the system will shut down immediately.
If the measured speed is within range, it is used to make minor
adjustments to the speed output when it is determined that the
actual speed and measured speed differ by more than 0.08 mph.
These small adjustments (1:1024) are only allowed to be at 4
second intervals to provide for the settle time of the motor and
heavily averaged speed input.

Elevation Control

The elevation control process works as follows: The host will
send an elevation command "GXXX0<CR>" to the processor
68 T2100-ST1 Treadmill, 110V / T2100-ST2 Treadmill, 220V 2097937-002 Rev G
11 March 2019